By THOMAS L. FRIEDMAN — The New York Times.

President Obama’s visit to China this week inevitably invites comparisons between the world’s two leading powers. You know what they say: Britain owned the 19th century, America owned the 20th century, and, it’s all but certain that China will own the 21st century. Maybe, but I’m not ready to cede the 21st century to China just yet.

Why not? It has to do with the fact that we are moving into a hyperintegrated world in which all aspects of production — raw materials, design, manufacturing, distribution, fulfillment, financing and branding — have become commodities that can be accessed from anywhere by anyone. But there are still two really important things that can’t be commoditized. Fortunately, America still has one of them: imagination.

What your citizens imagine now matters more than ever because they can act on their own imaginations farther, faster, deeper and cheaper than ever before — as individuals. In such a world, societies that can nurture people with the ability to imagine and spin off new ideas will thrive. The Apple iPod may be made in China, but it was dreamed up in America, and that’s where most of the profits go. America — with its open, free, no-limits, immigrant-friendly society — is still the world’s greatest dream machine.

Who would cede a century in which imagination will have such a high value to an authoritarian society that controls its Internet and jails political prisoners? Remember what Grandma used to say: Never cede a century to a country that censors Google.

But while our culture of imagination is still vibrant, the other critical factor that still differentiates countries today — and is not a commodity — is good governance, which can harness creativity. And that we may be losing. I am talking about the ability of a society’s leaders to think long term, address their problems with the optimal legislation and attract capable people into government. What I increasingly fear today is that America is only able to produce “suboptimal” responses to its biggest problems — education, debt, financial regulation, health care, energy and environment.

Why? Because at least six things have come together to fracture our public space and paralyze our ability to forge optimal solutions: 1) Money in politics has become so pervasive that lawmakers have to spend most of their time raising it, selling their souls to those who have it or defending themselves from the smallest interest groups with deep pockets that can trump the national interest.

2) The gerrymandering of political districts means politicians of each party can now choose their own voters and never have to appeal to the center.

3) The cable TV culture encourages shouting and segregating people into their own political echo chambers.

4) A permanent presidential campaign leaves little time for governing.

5) The Internet, which, at its best, provides a check on elites and establishments and opens the way for new voices and, which, at its worst provides a home for every extreme view and spawns digital lynch mobs from across the political spectrum that attack anyone who departs from their specific orthodoxy.

6) A U.S. business community that has become so globalized that it only comes to Washington to lobby for its own narrow interests; it rarely speaks out anymore in defense of national issues like health care, education and open markets.

These six factors are pushing our system, which was designed to have divided powers and to force compromises, into the realm of paralysis. To get anything big done now, we have to generate so many compromises — couched in 1,000-plus-page bills — with so many different interest groups that the solutions are totally suboptimal. We just get the sum of all interest groups.

The miniversion of this is California, which, as others have noted, is becoming America’s biggest “failed state.” Californians had hoped they could overcome their dysfunctional system by electing an outsider, a former movie star, Arnold Schwarzenegger. He would slay the system, like the Terminator. But he couldn’t.

Mr. Obama was elected for similar reasons. People had hoped that his unique story, personality and speaking skills could bring the country together, overcome paralysis and deliver nation-building at home. A lot of the disappointment settling in among Obama voters today is prompted by their dawning realization that maybe, like Arnold, he can’t.

China’s leaders, using authoritarian means, still can. They don’t have to always settle for suboptimal. So what do we do?

The standard answer is that we need better leaders. The real answer is that we need better citizens. We need citizens who will convey to their leaders that they are ready to sacrifice, even pay, yes, higher taxes, and will not punish politicians who ask them to do the hard things. Otherwise, folks, we’re in trouble. A great power that can only produce suboptimal responses to its biggest challenges will, in time, fade from being a great power — no matter how much imagination it generates.

Grandma said that, too.